Generally, polyarylate refers to a linear aromatic polyester resin prepared by poly-condensing an aromatic diol and an aromatic dicarboxylic acid. Such the polyarylate resin can have various molecular formulas depending upon its raw materials used. Among others, mention may be typically made of a polyarylate resin comprising the repeating units represented by the following formula 1, which is prepared by reacting bisphenol A as a bivalent phenol, and terephthalic acid or isophthalic acid as a di-carboxylic acid by polycondensation.

The polyarylate resin of the formula 1 is known in the art as an engineering plastic which is excellent in overall physical properties, and it can be widely used in the field of electric and electronic appliance part, for example, a switch, a socket, parts of a microwave, a relay case, and a plate since it has high heat resistance, excellent mechanical strength, and transparency. Further, in the mechanical field, it can be widely used as various raw materials or packaging materials to prepare various products, such as inner and/or outer parts of watches, parts of optical machines, parts of heating devices including a contact breaker of gas, lenses for a housing or an automobile, overall housing products, and instrument boards.
Examples of the process for preparing polyarylate include interfacial polymerization, solution polymerization and melting polymerization, and among these, the interfacial polymerization is widely used since it advantageously allows easy removal of the by-products and inhibition of an exothermic effect. In the interfacial polymerization for preparing polyarylate, a cationic catalyst for the phase transition can be added to increase a polymerization reaction rate.